Interfamily co-transfer of sensor and helper NLRs extends immune receptor functionality between angiosperms

Abstract

Plant nucleotide-binding, leucine-rich repeat (NLR) immune receptors recognize pathogen effectors and activate defense. NLR genes can be non-functional in distantly related plants (restricted taxonomic functionality, RTF). Here, we enable Solanaceae NLR gene function in rice, soybean, and Arabidopsis by co-delivering sensor NLR genes with their cognate NLR required for cell death (NRC)-type helper NLRs. In soybean protoplasts and in Arabidopsis plants, Solanum americanum Rpi-amr1, Rpi-amr3, and pepper Bs2 sensor NLRs confer cognate effector responsiveness if co-expressed with NRC helper NLRs. Rice carrying pepper Bs2 and NRCs recognizes the conserved effector, AvrBs2, and resists an important pathogen, Xanthomonas oryzae pv. oryzicola, for which no resistance gene is available in rice. Rice lines carrying sensor and helper NLR genes otherwise resemble wild type, with unaltered basal resistance or field fitness. Thus, interfamily co-transfer of sensor and helper NLRs can broaden the utility of sensor NLRs, extending the tools available to control diseases of rice, soybean, Brassica, and other crops.

Keywords: NLR immune receptors; crop disease resistance; effector-triggered immunity; helper NLRs; interfamily transfer; plant immunity; sensor NLRs.